The present invention relates to plastic siding panels for covering exterior walls on buildings.
Molded plastic siding panels for exterior building walls are known in the prior art. These molded panels are made from synthetic thermoplastic polymers, including polypropylene, polyethylene, and various mixtures and copolymers thereof.
Laterally elongated molded plastic panels are nailed to a wall support surface in horizontal rows partially overlapping each other in order to provide a pleasing appearance combined with a water-resistant protective layer over the support surface.
The molded plastic panels are typically installed by nailing several adjacent courses to a wall support surface, starting with a bottom course. A lower marginal edge region of each panel in courses above the bottom course overlaps a panel in the course immediately below. Side marginal edge regions of each panel overlap side marginal regions of adjacent panels.
The plastic panel of the present invention is fastened to a building wall by means of metal fasteners inserted through apertures on a nailing hem and through a fastening slot on a side flange. A principal objective of our invention is to provide a fastening slot that avoids fracturing or bowing of the panel when it contracts and expands in response to temperature changes.
A related objective of the invention is to provide a molded plastic panel having side marginal edge regions for interlocking laterally adjacent plastic panels without bowing or fracturing the panel during installation or upon thermal expansion and contraction.
A further objective of the invention is to camouflage spacings of varying width between adjacent panels resulting from thermal expansion and contraction.
Another objective of the invention is to provide a process for making a molded plastic panel including an attachment hem having at least one locking tab, without any through openings in the attachment hem behind the locking tab.
Additional objectives and advantages of the invention will become apparent to persons skilled in the art from the following detailed description.
In accordance with the present invention, there is provided a thermoplastic panel for covering exterior walls on buildings. The panel is made from a thermoplastic polymer selected from the group consisting of polyolefins, polycarbonate, polyvinyl chloride, and mixtures and copolymers thereof. Polyolefins, especially polypropylene in mixtures and copolymers with polyethylene, are particularly preferred. The thermoplastic panel is preferably manufactured by injection molding.
The thermoplastic panel includes a body, an attachment hem or nailing hem adjacent an upper portion of the body, a locking tab attached to the attachment hem, a bottom flange attached to a lower portion of the body, and at least one side flange extending laterally outwardly of the body.
The attachment hem is preferably adjacent an upper portion of the body. The attachment hem defines a plurality of spaced, laterally elongated attachment apertures or nailing apertures for attaching the panel to an exterior building wall.
A locking tab attached to the hem includes a downwardly extending lower leg portion and a forwardly extending upper leg portion connecting the hem with the lower leg portion.
A bottom flange attached to a lower portion of the body includes an upwardly extending locking lip for engaging a locking tab on an adjacent panel.
The panel body includes at least one laterally extending row of simulated shingles. The shingles each have a bottom wall extending between two side walls, and a front surface protion including a bottom end portion adjacent the bottom wall and a top end portion spaced upwardly from the bottom wall.
A particularly preferred panel body includes an upper row and a lower row of simulated shingles. A ledge, generally coplanar with the bottom wall of the upper row of shingles, extends rearwardly of the bottom end portion.
A lead fin extends laterally outwardly of the upper row of simulated shingles. The lead fin has a lateral end spaced laterally outwardly of the upper row. A groove below the lead fin extends between the lateral end and the upper row. Plastic panels of the invention fit together with a middle ledge of a first panel engaging a lead fin of a second panel adjacent the first panel.
A particularly preferred plastic panel includes at least one laterally extending row of simulated shingles having a simulated wood appearance. A panel with two rows of simulated shingles is most preferred. The simulated shingles each include a bottom wall extending between longitudinally extending shingle side walls. The side walls preferably are generally parallel to each other and parallel to adjacent side walls on other shingles in each row.
Opposed side walls on adjacent simulated shingles define a plurality of gaps each having a predetermined width, defined herein as the average distance between opposite side walls. These gaps each have a width that varies randomly within predetermined limits in order to camouflage the lateral spacings between adjacent panels that vary because of thermal contraction and expansion. For example, systems mounted with xc2xc inch average lateral spacings between shingles in adjacent panels will have gaps between adjacent simulated shingles averaging about a xc2xc inch width. However, the gap width varies randomly between about xe2x85x9 inch and ⅝ inch, thereby camouflaging spacings that vary because of thermal contraction and expansion.
In a preferred embodiment of the invention, the plastic panel is injection molded to include a body having side walls on opposite lateral sides, a top wall extending between the side walls, and an elongated strip extending outwardly of the top wall. The strip includes a locking tab spaced from the top wall and a laterally extending folding hinge between the locking tab and the top wall. The folding hinge extends between the side walls and has reduced thickness compared with the remainder of the strip.
The strip is folded along the folding hinge so that adjacent opposed surfaces on the strip define a fastening line. The opposed surfaces are then joined together by heat or ultrasound or mechanically to form an integral structure.
An important advantage of the invention is that the locking tab is continuous, extending without interruption between the side walls and without any openings behind the locking tabs.
The attachment hem defines at least one aperture, and preferably several apertures, for fasteners to attach the plastic panel to a building wall. At least one side flange extends laterally of the body, preferably laterally of a lower row of the simulated shingles. The side flange defines a fastening slot for inserting a fastener therethrough to attach the panel to a building wall.
The fastening slot extends at a predetermined acute angle relative to horizontal. More specifically, the fastening slot extends at an angle of about 5-30xc2x0 relative to horizontal, preferably about 10-20xc2x0, and about 15xc2x0 in a particularly preferred embodiment wherein the panel has dimensions of about 64 inxc3x9714 in. The fastening slot is preferably narrow and elongated, extending between opposed, upper and lower marginal edges. The head of a metal fastener extending through the slot overlaps both the upper and lower marginal edges.